Scientists Test Engineered Bacteria as a Potential Way to Prevent Type 1 Diabetes

Type 1 diabetes occurs when the immune system mistakenly destroys the beta cells in the pancreas that produce insulin. Current treatments help manage blood sugar, but they don't restore the immune system's ability to tolerate these cells or stop the attack. Scientists have long searched for ways to reset this broken immune tolerance, and a new approach involves an unexpected tool: engineered bacteria.

Researchers have designed a strain of bacteria to produce indole, a small molecule that may help regulate immune responses. The bacteria used in this study is a weakened version of Brucella melitensis, engineered so it cannot cause disease but can still produce the immunomodulatory compound. The idea is that a single intravenous dose of this engineered bacteria could shift the immune environment in the pancreas toward tolerance.

This approach differs from traditional vaccines or immunotherapies. Rather than directly blocking immune cells, the engineered bacteria aim to produce a metabolite—a chemical product—that naturally dampens excessive immune activation.

Scientists injected this engineered bacteria into female mice that are genetically prone to developing type 1 diabetes. Over the following weeks and months, researchers monitored blood glucose levels twice weekly to track whether and when diabetes developed. They defined diabetes as sustained blood sugar levels of 250 mg/dL or higher.

At the end of the study, the team examined pancreatic tissue in detail. They looked at insulin-producing cell survival, used specialized imaging to map 25 different immune markers, and analyzed individual immune cells at the genetic level. This comprehensive analysis revealed how the engineered bacteria influenced the immune landscape inside the pancreas.

This laboratory study demonstrates that a single dose of immunomodulatory engineered bacteria can affect both the timing of type 1 diabetes onset and the immune cell populations within the pancreas in animal models. The approach is still in early stages and has only been tested in mice.

Before this strategy could be evaluated in people, researchers will need to confirm its safety and effectiveness in additional preclinical studies. The goal remains the same: finding ways to prevent or delay type 1 diabetes by restoring immune tolerance rather than simply managing blood sugar after the disease develops.

Source: Journal of visualized experiments : JoVE. Evidence type: PubMed indexed literature. Type1Cure is an information and intelligence hub, not a medical advice service. This article summarizes published research and does not provide diagnosis, treatment, or personal medical guidance. Always talk to your own care team before changing anything about your Type 1 diabetes management.